Firearm



H. D. ALLYN FIREARM July 19, 1960 7 Filed June 25, 1957 4 Sheets-Sheet 1 H. D. ALLYN July 19, 1960 FIREARM Filed June 25, 1957 4 Sheets-Sheet 2 vwawaa v 6 Zy/ W H. D. ALLYN FIREARM July 19, 1960 4 Sheets-Sheet 3 Filed June 25, 1957 H. D. ALLYN July 19, "1960 FIREARM 4 Sheets-Sheet 4 vlllrl rizvllld Filed June 25 1957 Patented July -l. 9, 96f) FIREARM Harold D. Allyn, 1 Sumner Ave, Springfield, Mass.

Filed June 2'5, 1957, S81. No. 667,883 4 Claims. (Cl. 89--.l99)

invention is directed to new and useful improvements in a firearm of the autoloading, jet piston type which comprises a number of component parts, none of which are objectionably small and/or intricate, the plurality of which may be economically made from stampings or screw machine stock, and all of which are of adequate configuration and/or dimension so as to provide par-ts having such strength .as to enable them to tion of components including a hammefia'nd scar and withstand the shocks normally encountered in autoload- 7 The action of the firearm of this invention is accomplished without the usual multiplicity of associated component parts familiar in firearms of the type herein contemplated.

The concept of the firearm hereof has been developed with attendant manufacturing problems fully in mind and with particular regard to the possibility of producing many of the component parts hereof from riveted or welding st-ampings, screw machine parts, or from fabrications made by like systems of low cost manufacture, liberal tolerances being permitted practically throughout the structure so as to further aid in the economics of production.

It is a principal object hereof to provide a new and novel combination of components including a reciprocatory slide block and .a pair of spaced action bars reciprocatory therewith and a breech block movable both longitudinally with the slide block and movable vertically with respect thereto. The slide block assembly oifers a very favorable weight ratio .to the breech block in that the hammer, hammer spring, sear and sear spring are mounted on or carried by the slide block instead of on the trigger assembly, as is normally the case, and hence said components serve to .give additional weight to the slide block assembly whereby a more favorable weight ratio between the operating shaft or rod and the breech block is oifered.

It is another object hereof to provide means for permitting considerable pretravel of the reciprocating slide block, on the rearward movements thereof, before same contacts the breech block and carries same rearwardly therewith.

A still further object hereof is to provide a slide block assembly which may be actuated by action bars extending forwardly therefrom to a suitable gas piston and spring assembly, the slide block assembly being suitably guided for reciprocation in the receiver, and the slide block and breech block each being provided with cooperating surfaces for the locking function during The invention further envisions an improved combination hammer and trigger action which provides a mechanism that functions as a buffer at the termination of the rearward or opening stroke whereby the buffer absorbs the shock or blow connected with the abrupt stopping of the components at the termination of said rearward or opening stroke whilst the hammer component is cocked preparatory to firing or retiring.

As another object hereof, I provide a novel combinatheir related springs which are grouped with and supported by the slide block whereby the reciprocation of said components with the breech bolt is permitted.

It is a further object to provide such other structural and operational improvements in mechanisms of the class to which reference has been made, as will hereinafiter appear. For instance, by the use of a coin or equivalent object, the barrel and receiver assemblies may be quickly and easily removed from the stock, following which, all parts attached thereto, excepting the hammer and sear and related springs, may be readily disassembled Without any further use of tools. By unscrewing an additional screw, the entire trigger guard assembly can be removed from the stock .and all parts thereof may be easily disassembled without the use of any tools whatever.

Another purpose is to provide a new and useful means for attaching the action bars of a gas operated firearm to the gas piston and its related mechanism and to provide a combination piston bearing and spring guide rod, and a simple one piece retaining ldetent which prevents said rod from'loosening through the vibrations of repeated firing. I

Additionally, it is an object hereof to provide a firearm action which will operate smoothly and'with a relatively high degree of freedom from the usual and normal malfunctions.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

It will be appreciated that the utility and application of the construction hereof extend beyond any one particular kind of firearm and comprehend the same new and useful features when incorporated in any other reasonably appropriate type of firearm.

In other words, this specific example of a physical embodiment of the invention is to be considered in all respects as being merely illustrative. All modifications and variations as reasonably fall within the meaning and range of equivalency of the disclosure and claims hereof are therefor intended to be embraced herein. Although a complete autoloading, bottom ejecting n'fle having a detachable side feeding box type magazine is shown, any of the component parts or groups of partsmigh-t find similar applications in other types of firearms, all within the spirit and scope of this invention.

Other objects and novel features of the invention will be more clearly and fully set forth in the following specification and the accompanying claims and will become more apparent from a study of the description in connection with the attached drawings wherein:

Fig. 1 is a broken top view of the firearm of the invention;

Fig. 2 is a broken side elevational view of the firearm shown in Fig. 1 with the action in the closed position;

Fig. 3 is a partial bottom plan view of the firearm shown in Figs. 1 and 2 showing the bottom ejection p Fig. 4 is a partial longitudinal sectional view on the line .4--4 of Fig. 8;

Fig. 5 is a partial longitudinal sectional side elevational view showing the rear portion of the operating mechanism with the action in the open position;

Pig. 6 is a partial sectional view on the line 6-6 of Fig. 8;

Fig. 7 is a sectional view on the line 7-7 of Fig. 5;

Fig. 8 is a view similar to Fig. 5 with the action in the closed position;

3 Fig. 9 is a partial sectional view on the line 9-9 of Fig. 8;

Fig. 10 is a sectional view on the line 10- 10 of Fig. 8;

Fig. 11 is a view similar to Fig. 10 v he line 111411 of Fig. 8;

Fig. 12A is a partial sectional View on the line 1'2-12 of Fig. 13 showing one system of attaching a fore-end cover to the barrel;

Fig. 12B is a partial sectional view on the line 12-12 of Fig. 13 showing another system of attaching the foreen d cover to the barrel;

Fig. 1.3 is a partial longitudinal sectional view of the firearm forward of the breech block and bedding plate;

Fig. 14 is a sectional view on the line 14..14 of Fig. 13;

Fig. 15 is a view similar to Fig. 14 on the line 15-15 of Fig. 13;

Fig. 16 is a perspective view of the front end portion only of the right hand action bar;

Fig. 17 is a sectional view on the line 1717 of Fig. 13 showing the action bars, the action bar clip, the recoil springs, the piston block, the cylinder block, detent clip, and the guide rod;

Fig. 18 is a perspective viewv of an action bar clipof the invention as made from a stamping;

Fig. 19 is a perspective view of an action bar clip of the invention, similar to the action bar clip of Fig. 18 but made from a bar of solid, stock as contrasted with a stamping; and

Fig. 20 is an enlarged sectional elevational view of the operating handle pivot and associated components shown inFig. 8.

In. the following description and claims, various details will be identified by specific names for convenience.

The rear cap 8 is provided with a plurality of detent cuts 37 around the outer periphery thereof. See Figs. 8

, and 11.

A rear cap detent 40 comprises a unitary, spring memher which is generally triangular in shape. Said detent has one end portion seated in a centrally disposed, vertically extending opening in the buffer plate 32 and its opposite end portion seated in a centrally disposed substantially horizontally extending opening in the bufier Thesenames; however, are intended to be as generic in their application as the art will permit.

Referring to the drawings by characters of reference, it. will be seen that the illustrated firearm as shown in Figs. 1, 2 and 3, discloses the general outline of the weapon in outside views and comprises a stock 2, a stock butt 3, a fore-end cover 4, a barrel '6, a rear cap 8, a receiver. 10, a front sight 12, a rear sight 14, a magazine 16, a magazine catch 18, an operating handle 20, a trigger- 21, a safety 22, a trigger guard 24, a front bedding screw 26, a rear guard screw 28, a front bedding plate 30, a buffer plate 32, and a stock plate 34.

As shown, the magazine is on the right side of the firearm, though it might be disposed on the left side thereof with equally eifective results.

The receiver 110 is substantially roundin cross section, although not necessarily so, it conceivably being adapted to be rectangular or irregular in cross section, within the spirit hereof.

An opening on the upper side of the receiver 10 is in the form of a magazine cut which functions to receive the upper end portion of the magazine 16.

A gas vent hole (not represented) may be provided in aside of the receiver for the obvious purpose.

The bottom of the receiver 10 is cut away, and the interior thereof is hollowedas is conventional for the reception of components in the well known manner.

The rearmost extremity of the receiver 10 is provided with an annular tongue 36- and a rearwardly facing opening. The tongue 36 is receivable in a mating annular transverse opening in the vertically extending portion ofa buifer plate 32. Such feature serves to prevent any spreading of the open bottom portion ofthe receiver 10 following assembly.

Arear cap 8 is threadedly engageablethrough the opening in the buffer plate with the 'rear end of the receiver. It will be indicated here and-will be hereinafter more fully appreciated that the rear cap is one of two means serving. to. hold'thereceiver barrel and slide block' assemblies Ielativeto the stock.

plate. The buifer plate adjacent the transverse annular opening has a vertically extending slot so as to permit the detent to be depressed downwardly. Said detent is retained therewithin by means of its own spring tension. The intermediate portion of the detent between the end portions serves as a click detent in the detent cuts 37 on the rear cap 8 so as to prevent the rear cap 8 from loosening due to autoloading firing. The detent 40 is capable of assembly and disassembly from the bufier plate 32 without any special tools therefor being necessitated.

The trigger-hammer mechanism, now to be described, is essentially the equivalent of the mechanism shown and described by me in my application filed June 19, 1956 bearing Ser. No. 592,430.

The lower extremity of the buffer plate 32 is provided with a horizontally and forwardly extending portion 32' and a pair of parallel forwardly and vertically extending wing-like side walls 31 extending upwardly therefrom and outwardly away from the upper vertically extending portion thereof, as will be observed by reference to Figs. 8 and 11.

A buffer plate bolt 3' extends through the butt 3 and the buffer plate 32 whereby said bufier plate is held firmly against the L-shaped bedding surface provided on the upper inner wall of the stock, as may be appreciated by reference to Figs. 5 or 8.

The rear extremities of the trigger guard 24, the stock plate 34 and the trigger housing (shortly to be described) are disposed one above another, as shown in Fig. 8, and are secured relative to the underside of the stock by means of a rear guard screw 28, which screw is threadedly engageable with the buffer plate 32 for assisting in thesecurement of same relative to the stock.

A front guard screw 50 secures the forward extremity of the trigger guard 24 to the stock plate '34 and the trigger housing disposed thereabove.

The trigger housing includes a pair of transversely spaced vertically extending side walls 42 connected together by a lowermost transverse horizontally extending bottom wall 41 which if desired, may be of double thickness at its opposite forward and rearward ends whereby the screw means 28 and/or 50 may be better engaged therewith.

The trigger 21 is an irregularly shaped member having a lowermost downwardly depending finger engageable portion of conventional configuration and a bifurcated portion extending vertically upwardly therefrom to provide a pair of spaced ears 21.. Said'ears extend upwardly through appropriately aligned slots in the bottom wall of the trigger housing and the stock plate in a manner whereby each of the ears is disposed adjacent a corresponding side wall 42 of the trigger housing;

The trigger 21 is pivotally mounted relative to the trigger housing by means of a pair of trigger pivot pins58 of any desired form, each trigger pin'being engageable with and extending through appropriately aligned openings in one of the said ears and the adjacent side wall 42 of the trigger housing.

A generally U shaped elongated connector 62 has spaced parallel upwardly extending. side walls connected by a lower horizontally disposed bottom'wall in the rearward portion thereof. The rear extremity of the. connector 621's receivable within the slotof the trigger so as to .be disposed between the spaced ears thereof;

The connector is provided'with a downwardly-depends ing lug portion 63 having a laterally disposed right angu-, lar slot 65 extending therethrough. The upper face of said lug portion is provided with an inclining-declining connector ramp or cam surface 66. i

A connector pin 60 extends transversely through the slot 65 and through appropriately aligned transverse openings in the ears of the trigger. Opposite ends of the pin 60 abut the side walls of the trigger housing, which walls function to hold the pin in situ.

The connector reciprocates'along its horizontal axis forwardly and rearwardly and along its vertical axis upwardly and downwardly within the limits ofthe pin 60 extending through the slot 65.

As shown in Fig. 5, the pin 60 is disposed atthe bottom of the vertically extending portion of the slot 65 wherefor the connector will be understood to have assumed the topmost position on its own vertical axis.

A generally U-shaped unitary safety-trigger-connector spring 68 includes a pair of spaced side portions which are disposed adjacent opposite outer sides of the trigger housing and a transverse midsection at the forward end thereof connecting therebetween.

Said side portions have loops intermediate their ends which are engageable over the outer ends of the adjacent trigger pivot pins58.

The transverse midsection of the safety-trigger-connector spring at the forward end thereof passes beneath the connector 62 where it serves to push upwardly and forwardly against a downwardly depending protrusion or lug 67 on theunderside of the connector 62.

The rear end of one side of the spring is in the form of a U having a forward free end receivable in a suitable opening in the trigger 21 serving to hold the trigger normally under a forward tension and hence in the well known forward ready-to-fire position. i

The, rear end of the other side of the safety-triggerconnector spring is bent transversely inwardly and provides an upward tension as a safety detent spring.

The safety 22 is pivoted on a safety pivot pin 56 which extends transversely therethrough and is supported at its opposite ends by the side walls of the trigger housing.

A transverse opening is provided through the safety, which opening is provided in its upper wallwith a pair of detent notches, same being a forward detent notch 23 and'a rearward detent notch 23'.

The aforesaid end portion of the safety-trigger-connector spring functions as a safety detent spring by en gagement in one or the other of the notches 23 and 23'. When the spring is in the forward detent notch 23, it serves to hold the safety in the Oif position; when in the rearward detent notch 23, it holds the sfety in the On position.

Lowermost sections of the side portions of the safetytrigger-connector spring bear on the opposite sides of the upper portion of the upper wall of the stock plate 34, as shown.

The transverse midsection of the safety-trigger-connector spring at the forward end thereof constantly exerts a forward and upward pressure ,on the connector and holds the front end of the connector against the underside'of the action bars 94, as shown in Figs. and 8.

It will be noted here, with reference once again to the safety mechanism that same functions to prevent inadvertent trigger operation when the firearm is loaded and cocked. The safety is pivoted to the trigger housing rearwardly of and in alignment with the trigger and is movable between a locking position of locked engagement with the trigger for preventing the rearward movement thereof and an unlocked position of unlocked engagement with the trigger for permitting the rearward movement thereof upon the firing of the gun. The trigger guard is slotted at its rearward portion so as to permit the safety to travel forwardly and rearwardly therethrough, as shown.

A hammer 70 is mounted on a hammer pivot pin 71 which extends through and is supported by a pair of spaced action bars 94 and 94 and a slide block 92 disposed therebetween. The rear face of the slide block is slotted so as to receive said hammer. The hammer is mounted forpivotal movement between a rearward cock position and an upward fire position and is arranged to be pivoted to the cock position in a manner shortly to be described.

The hammer is held under the tension of a U-shaped mouse-trap or torsion type hammerspring 72 which is looped around the hammer pivot pin 71 on opposite sides of the hammer with the spaced opposite lower free ends thereof being brought to bear in the slots of the slide block 92. The transversely extending midsection bears against the rearmost face of the hammer. Thus, the spring biases the hammer from cock to fire position upon the release thereof.

A sear 75 is pivotally mounted on a sear pin 78 extending laterally through the slide block 92 and action bars 94 and is retained in place by the front ends of the hammer spring 72. See Fig. 10. The sear holds the hammer in the cock position and prevents the swing or throw thereof until release by the actuation of the trigger.

The sear is provided with an uppermost hammer engaging point 76 which engages a complemental and mating sear engaging notch in the hammer.

The hammer is held relative to the sear through the hammer engaging point which engages the sear engaging notch of the hammer by w'rtue of the tension exerted by a sear spring nesting in an opening in the slide block. The sear spring exerts a normally downward or outward pressure against the sear.

As the connector is pulled rearwardly upon rearward movement of the trigger, the sear is moved clockwise and the sear spring is compressed inwardly into its opening in the slide block whereby the hammer engaging point of the sear is released from engagement with the sear engaging notch in the hammer to fall and discharge the firearm.

The action bars and slide block and the hammer and sear and their related components may be manually or automatically actuated rearwardly.

As they are so rearwardly moved, the tail 74 of the hammer 70 passes between the side walls of the connector and contacts the connector ramp. Continuing rearwardly, the hammer is pivoted as the hammer tail 74 contacts the lowerforward end of the bufier plate 32 whereby the upper portion of the hammer is receivable between the spaced side walls 31 of the bulfer plate. See Fig. 5. In this manner, the hammer is actuated to the cock position.

Immediately after the hammer has reached a full cock position, the flat 74' on the rearward face of the hammer strikes the buffer plate 32 whereby the cocking action becomes increasingly diificult or hard and the operating mechanism is slowed down accordingly.

The front faces of the side walls 31 of the buffer plate 32 serve as stops for receiving the abutting rear end of the slide block at the termination of the rearward stroke.

When the hammer is pivoted into the full cock position, the sear point, under the tension of the sear spring, moves into the sear notch in the hammer.

The hammer is allowed a slight overtravel to a position beyond the full cock position so as to make a slight gap between the sear point and the sear notch before the rear end of the mechanism abuts the buffer plate so as to bring the components to a full stop at the limit of the rearward stroke. Such limit determined by the abutment of the rear face of the slide block against the buffer plate, as'best shown in Fig. 5.

The cocking of the hammer against the hammer spring functions as -a buffer and brings the hammer, slide block, breech block and attached mechanism to a slow stop, all to the end that jarring is minimized. I

When the operator cocks the firearm manually, he

cocks only on the easy portion of the stroke. On the hard or diflicult portion of the stroke, where the hard cocking portion on the hammer contacts the contacting surface of the buffer plate, it is not necessary for the operator to overcome the additional force encountered, the recoil mechanism accomplishing this automatically whereby buffer effect is obtained. Such feature justifies the overtravel of the sear in that the sear has moved past the sear notch on the hammer before the hard portion of the stroke is reached. 7

When the slide block and attached mechanism are moved forwardly by the recoil springs, so as to load and close the firearm, the hammer, under tension of the harm mer spring, pivots slightly forwardly on the hammer pivot pin until the sear notch of the hammer contacts the sear point of' the sear.

The hammer remains in this full cock position until released by the trigger at the completion of its cycle.

Further reference will now be made to the connector.

The connector is movable rearwardly from what will be referred to as its upper and forward position, shown in Fig. 8, by means of the connector pin 60 which is fixed to the trigger. As the trigger is actuated rearwardly upon its pivots, the pin 60 is swung rearwardly wherefore the connector is moved rearwardly.

As the slide block assembly moves forwardly, the hammer tail rides on the ramp 66 wherefore the con- .nector 62 is cammed downwardly against the upward and forward pressure of the safety-trigger connector spring at the forward end of said spring at its point of engagement with the connector.

The connector is fixed to the trigger by means of the trigger pin 60 in the slot 65 and the connector moves forwardly when the ramp thereof is sufficiently depressed so as to free the connector pin from the vertical portion into the horizontal portion of the slot whereupon the safety-trigger-connector spring urges the connector forwardly by the transverse portion thereof acting on the lug 67.

The connector is stopped in its forward travel when the forward face of the lug 63 abuts the lower transverse wall in the slot in the wall of the trigger housing.

At this point, the connector pin contacts, or nearly contacts, the rearward end of the horizontal portion of the angular slot.

When the trigger is released, pressure of the rear end of the safety-trigger-connector spring forces the trigger forwardly.

The connector pin, 'held snugly in the trigger, moves forward with the trigger along the horizontal portion of the angular slot until stopped by the front end of the slot.

As the connector is under the upward as well as the forward tension of the safety-trigger-connector spring, the rear of the connector pivots upwardly and the connector pin moves into the lower portion of the slot to the position shown in Fig. 8.

Inasmuch as the firearm hereof is of the side-loading, bottom-ejecting, type, the forward extremity of the connector 62 is split so as to permit the cartridge or shell to be ejected downwardly therethrough and out through the bottom of the firearm.

The lower portion of the sear 75 is split in the form of an inverted T, each end of which is contacted by the connector, when the trigger is pulled to discharge the firearm. See Fig.. 10.

.Each side of t-hefront of the connector 62 has an upwardly extending portion which carries on its upper side a connector hook 64. The hook is engageable in a matingnotch in the sear 75, as the trigger is pulled rearwardly to discharge the firearm. As the trigger is pulled, the hook of the connector is locked vertically into the sear, thereby eliminating any. possibility of the connector slipping downwardly off the sear. See Figs. 8 and 5.

The operation of the magazine 16 is described in a copending application filed herewith and the rim retainer and the ejector and their methods of operation are likewise described in another copending application, filed herewith.

The slide block and related components will now be described.

The slide block 92 is centrally hung between a pair of spaced, parallel, action bars 94 (see Figs. 8 and 9), being attached thereto by soldering, brazing, riveting, or equivalent means.

The front end of the slide block 92 is supported by the action bars 94, same being slidable in slots on opposite sides of the front bedding plate 30, as shown in Fig. 7.

The upper rear portion 98 of the slide block 92 supports the rear of abreech block 99 (see Figs. 8 and 10), which breech. block is of a configuration and dimension complementary to the inside of the receiver 10 and is reciprocal relative thereto, as is conventional.

The rear end portion of the slide block is suitably grooved and the grooves are accommodated in a T slot 102 in the receiver 10. See Fig. 10. This feature is disclosed in my application filed Feb. 17, 1956 bearing Serial Number 566,267.

This feature effectively prevents lateral and vertical movements of the slide block and yet allows sufl'icient clearance to permit the slide block to reciprocate freely within the receiver 10.

In Fig. 13, a cylinder block 400 is shown as being soldered, brazed or otherwise attached to the barrel 6.

A gas vent 402 is drilled through the cylinder block 400 and communicates with an aligned opening 404 through the lower portion of the barrel 6.

A screw plug 406 is receivable in the lower portion of the gas vent 402 to seal off same.

A hollowed piston block 410 is provided with an integral cylindrically shaped forward end portion 412 which functions as a gas piston.

The piston 412 is provided with a longitudinally-extending horizontally-disposed bore through which the forward end of a guide rod 420 extends whereby the piston block 410 slides freely relative to the guide rod 420.

A compressible detent spring clip 422 fits into a transversely extending slot through the forward end of the guide rod 420 as shown in Fig. 13.

The detent spring clip 422 is a unitary structure and is formed from spring Wire or equivalent material.

Upon assembly, it is compressible so as to be receivable in the slot of the guide rod 420 and to be held therein and relative thereto by its own spring tension.

The forward extremities of the pair of action bars 94 and 94 are rounded and the forward end portions are reduced in thickness, as best shown in Fig. 16, so as to be receivable in correspondingly rounded slots in the piston block 410. The inner sides of the action bars are slotted at 94' slightly rearwardly of the forward ends thereof to receive the action bar clips now to be described.

Longitudinal movement between the action bars 94 and the piston block 410 is prevented by the action bar clip, generally designated by the numeral 430 in Fig. 19 and by 430 in the modified form shown in Fig. 18.

T he action bar clip comprises a pair of spaced vertically extending side wall members 432 connected together by a transverse bottom wall member 434.

In the modified form of Fig. 18, the side walls are designated as 432 and the bottom wall as 434'.

The side walls 432 of the action bar clip 430 are receivable in the appropriately aligned slots 94 on the inner sides of the action bars 94 and the piston block 410.

As aforesaid, by this arrangement, longitudinal movement between the action bars 94 and piston block 410 is prevented.

Vertical movement is prevented as the rounded end portions of the action bars are receivable into correspondingcircular grooves inthe piston block 410.

estates "9 t The action bars are secured at their rear endportions to a slide block 92 as previouslyindicated.

The action bars are maintained in a parallel and spaced relationship, as to each other by means of the slide block at the rear extremities thereof and by the piston block atthe forward extremities thereof. 7

On assembly of the piston block 410 and the action bars 94, the forward ends of the action bars are pushed. forwardly into the appropriate mating slots in the piston block.

The action b ar clip is embraced around the piston block with the upper inwardly extending ears 436 in Fig. 19 (and 436' in Fig. 18) engagingthe top. of the piston block 410, as best shown in Fig. 14.

The inward spring tension of the action b-ar clip insures a tight fit thereof around the piston block.

When the action bars are assembled into the piston block, the slots in the action bars are aligned with the slots in the piston block wherefor the side walls of the action bar clip can be pushed into and through the slots.

The tapered ears 436 of the action bar clip provide camming surfaces so as to cause the side wall members of the action'bar clip to spring outwardly as they are pushed into the assembled position.

With the action bar clip pushed upwardly as far as it will go, the ears snap inwardly under spring tension provided by the transverse bottom wall 434 and are held thereat.

To disassemble, the ears 436 may bepried outwardly by an operators fingers so as to release the ears from their mating engagement with the top of the piston block. The lower wall of the action bar clip may then be manually engaged so as to be downwardly withdrawn.

A recoil spring is provided and comprises a small diameter spring 440 which is wound right hand (or left hand if desired) and a large diameter spring v442. which is Wound opposite from the winding of the small diameter spring. 1

By means of the two springs, a spring action more nearly like that of a spring which is longer than space permits in this instance is achieved.

By means hereof, I obtain a softer .spring action and a more desirable scale to the spring while keeping down the fiber stress as is Well known.

To assemble the springs into the firearm, the action 9 which is disassembled from the stock is placed in the closed position. 7

The guide rod 420 is pushed through the front end of the cylinder block 400 and the piston block 410.

The guide rod 420 is moved slightly rearwardly and the springs 440 and 442, assembled one inside the other, are pushed forwardly on the guide rod, the feedingbeing from the rear end of the guide rod.

With the springs on the guide rod, the guide rod may be screwed into the front bedding plate 30.

The guide rod is screwed into the plate 30 until the detent spring clip 422 is brought into engagement with the plurality of radially disposed detent cuts or slots 444 in the forward face of the cylinder block 400 in the conventional manner.

The slots 444 may be U shaped or if desired may be cone or cup shaped openings of suitable depth to receive the spring clip 422.

The forwardly facing wall of the piston 412 around the guide rod 420 is provided with an annular concaved ring providing a pair of sharp edges which function as scrapers and assist in keeping the guide rod and the inside wall of the cylinder free of carbon and fouling accumulation. 'An annular portion of the piston block 410 immediately to the rear of the piston 412 is concaved to act as a gas deflector and to deflect gases forwardly when the piston leaves the cylinder during the operation of the firearm.

In operation, after the cartridge is fired gun functions by a means now to be described.

tance identified herein as pre-travel.

After the bullet passes the aligned gas vent openings 464 and 402, gas passes from the barrel therethrough under high pressure to the piston chamber and strikes the piston head 412 a sharp blow, as is conventional and well known, whereby the recoil energy ofthe discharge of the firearm is transmitted to the piston and to the recoil springs.

After the inertia of the slide block assembly has been overcome, movement of said assembly rearwardly is initiated.

The assembly includes the piston block 410, the action bar clip 430, the pair of action bars 94, the slide block 92, the hammer 70, the hammer pivot pin 71, the hammer spring 72,-the sear 75, the sear spring 80, the sear pin 78, the operating handle 20, the operating handle retaining plunger 113, the operating handle retaining spring 114, and the operating handle pivot 116.

The slide block assembly initially travels a short dis- In the design of the firearm, I have provided for as much as 0.5 pretravel of the slide block assembly. The pre-travel distance may be varied or controlled during manufacture as desired. This oifers the bullet an opportunity to have left the muzzle'whereby the chamber pressure is sulfii buffer plate 32.

ciently reduced so as to facilitate easy extraction.

Following the pre-travel, the cam face 118 of the slide block 92 contacts the cam face 120 of the breech block 99.

As the face 118 contacts the face 120, it forces the front end 122 of the breech block 99 downwardly thereby causing the locking lug surface 124 of the breech block 99 to become disengaged from the mating locking surface of the receiver 10.

The slide block assembly then travels rearwardly in the conventional manner by means of the force imparted to the front end of the piston 412 by the gas'resulting from the explosion of the cartridge as is well known.

I have made the weight of the slide block assembly greater than the weight of the breech block thereby enabling the former to hold its momentum as it carries the latter with it to the rear. 7

During this period of rearward travel, the cartridge is ejected by the ejector 127 and the hammer 70 is cocked by means of the hammer tail 74 striking the The recoil springs meanwhile have been compressed.

During its forward travel, by means of the recoil springs releasing their tension, the breech block 99 picks up a cartridge from the magazine 16 and retains the rear end of the cartridge by means of the rim retainer 128 and feeds it into the chamber 130 of the barrel 6.

A description of the feeding of the cartridges from the magazine to the chamber is covered in my copending application filed June 25, 1957 as Ser. No. 667,924, now Patent No. 2,908,987.

When the breech block 99 reaches its forwardmost position, the lower surface 132 of the breech block 99 strikes aligned surfaces 134 of the receiver 10 and barrel 6 and the rear cam of the slide block then contacts the lower rear camming surface of the breech block forcing the forward end upwardly.

When the firearm is fully closed, the upper supporting surface 136 of the slide block 92 contacts a complementary lower supporting surface of the breech block and retains the front end of the breech block in the locked position. See Fig. 8.

It is to be appreciated that it is impossible to discharge the firearm until the breech is fully closed and locked. When the hammer is down in the fired position shown in Fig. 8, the forward face of the hammer strikes the rear vertically slotted portion of the slide block. a

The vertically slotted portion of the slide block starts to move rearwardly the instant the slide block moves to the rear thus making contact of the hammer face with '11 the firing pin impossible until the slide block is again in its forwardmost position.

The rear of the slide block is slidably retained in the lower portion of the receiver in the aforedescribed T slot.

The operating handle 20 is attached to the operating handle pivot 116 by means of welding, brazing or equivalent means. If desired, the handle and pivot could be made as one piece. I

The pivot 116 is provided with a flat portion 142 that is contacted by the fiat bottom surface 144 of the operating handle retaining plunger 113 under the spring pressure of the operating handle retaining spring 114. See Fig. 20.

In this way, the operating handle 20 is retained in the slide block 92. See Figs. 5, 8, 9 and 20.

To remove the operating handle 20 from the slide block 92, when the slide block assembly is removed from the stock 2, it is only necessary to rotate the operating handle 20 in either direction and the flat portion 142 will earn the operating handle retaining plunger 113 upwardly, allowing the operating handle 20 to be withdrawn from the slide block 92.

' It may be reassembled by pushing the operating handle retaining plunger 113, containing the spring into the opening 146 in the slide block 92 with a nail or the like.

When the plunger is fully seated, the operating handle may be pushed in place and the nail withdrawn.

The front end 148 of the firing pin 150 may also be used as an assembly pin.

The flat bottom surface 144 of the operating handle retaining plunger 113 contacting the flat portion 142 of the operating handle pivot 116 under the pressure of the operating handle retaining spring 114 will keep the operating handle in a vertical position, as shown in Fig. 9.

When the firearm is in the assembled position, the side walls of the ejector slot in the stock plate 34 consistently holds the operating handle in the assembled position. See Figs. 9 and 10.

If it is desired to hold the action of the firearm in the open position, the operating handle may be pulled rearwardly until the handle can be pushed sideways into the notch 151 in the stock plate. See Fig. 3.

The action will then be held in the open position against the pressure of the recoil springs 440 and 442.

By a sidewise push in the opposite direction from which it was set in the notch, the operating handle will snap out of the notch and the breech will close by the action of the recoil springs.

The receiver, barrel, and slide block assembly are held in the stock at two points only, first by the rear cap 8 screwing into the rear end of the receiver 10 through the buffer plate 32, and second by the front bedding screw 26 holding the front bedding plate 30, which is held onto the receiver by the barrel thread, as shown in Figs. and 8, securely down on the front bedding surface 155 of the stock 2.

Side motion of the front of the receiver in the stock 2 is prevented by the snug fit of the sides 156 of the stock 2 with the sides 157 of the front bedding plate 30, as shown in Fig. 7.

The front bedding plate 30 and the buffer plate 32 are the only contact points of the barrel and receiver assembly with the stock.

The assembled double action bars occupy a wider space in the stock than is occupied by the barrel just a few inches ahead of the chamber. Viewed from the top, an unsightly gap remains. I hide this gap from view by a a unitary fore end cover 4 made from plastic or other suitable material. See Figs. 5, 8, 12A, 12B and 13.

A semicircular tongue 158 fits into a corresponding groove 160 in the front bedding plate 30. A pair of downwardly depending clips 162A or 162B at the extreme front end of the fore end cover 4 act as spring snapsand hold the bottom surface 164 of the fore end cover 4 firmly against the top surface 166 of the stock 2. The spring tension of the clips 162A or 162B is provided by the inherent flexibility of the material from which they are made.

Forward'movement of the fore end cover 4 is prevented by the extreme front end of the clip contacting the inner stock surface 411 just forward of the front end of the square portion of the piston block 410, with the action in the closed position. See Fig. 17.

The form of clip, /2 of which is shown as 162A in Fig. 12A, snaps over the barrel 6 to retain the fore end cover 4 in place. However, if it is desired to keep the barrel completely free floating in the forward portion of the stock, the clip, /2 of which is shown as 162B in Fig. 12B, snaps into corresponding grooves 168 cut in the inner forward portion of the stock 2.

When the firearm is being carried loaded and cocked, with the safety off, one may inadvertently place his fingers in the ejection port, which is on the bottom of the firearm. If his fingers were able to contact the sear or a protruding portion of the connector, he might accidentally discharge the firearm. To prevent same, the sear is protected by the overhang of the rear lower portion 170 of the slide block 92, which will, owing to the narrow ejection slot prevent the fingers from contacting the sear 75. 7 An upwardly extending portion 174 of the stock plate 34 protects the downward depending portion 67 of the connector 62 from accidental contact by the fingers.

What it is desired to claim and secure by Letters Patent of the United States is:

1. In a firearm and including a stock and bar-rel and receiver and breech bolt, the improvement of a dual means for holding the receiver and barrel relative to the stock comprising: a first means including, a slotted buffer plate fixed to the stock and having an opening extending therethrough, the rearward end of the receiver having a rearwardly facing annular tongue circumferentially disposed adjacent an annular opening in the receiver, an annular rear cap threadedly engageable through the opening in said buffer plate with the rearward end of the receiver for holding the receiver and stock in locked engagement and having a plurality of detent cuts in circumferentially spaced relation on the outer periphery thereof, and a rear cap detent yieldingly held by said buffer plate and having a portion selectively receivable in one of the detent cuts on said rear cap; and a second means including, the breech end of the barrel being threadedly engageable with the receiver, a front bedding plate having an opening extending therethrough, said front bedding plate being receivable over the breech end of the barrel and held in abutting relation between the forward end of the receiver and the barrel, and a stock attaching member for extending through the stock and threadedly engaging said front bedding plate for attaching the stock to the barrel.

2. In the gun as set forth in claim 1, the improvement comprising, said rear cap detent having a portion extending into one of the plurality of detent cuts on said rear cap in seriatim as said rear cap is rotated relative to said buffer plate and the receiver.

3. In the gun set forth in claim 1, a combination of elements for partially absorbing the shock of the stoppage of the reciprocating components during the portion of cyclic operating at the termination of the rearward recoil stroke and for readying the components for the subsequent counter recoil stroke prior to firing comprising, a slide block engageable with the breech bolt for actuating the breech bolt between forward-locking and rearwardunlocking movements relative to the receive, a trigger pendulantly mounted relative to the receiver, a eammable spn'ng-tensioned connector slidably mounted on said trigger for movement along its horizontal axis substantially in the axial direction of said slide block into and out of operating position and for movement upwardly and downwardly along its vertical axis, said connector having an inclining-declining cam on the upper surface thereof, a sear pivotally mounted on said slide block, a hammer pivotally mounted on said slide block and reciproeable rearwardly on the rearward stroke of said slide block, said hammer being contactible with said buffer plate for actuation into a full cock position, said hammer and sear having complemental portions for holding said hammer in a cocked position during the forward movement of said slide block to the forward closed firing position, said hammer acting on the cam of said connector and camming said connector downwardly on the rearward and forward stroke of said hammer.

4. In a gun of the class described and including a stock and barrel and receiver and breech bolt, a slotted buifer plate fixed to the stock and having an opening extending therethrough, the rearward end of the receiver having a rearwardly facing annular tongue circumferentially disposed adjacent an annular opening in the receiver, an annular rear cap threadedly engageable through the opening in said buffer plate with the rearward end of the receiver for holding the receiver and stock in locked engagement and having a plurality of detent cuts in circumferentially spaced relation on the outer periphery thereof, a rear cap detent yieldingly held by said buffer plate and having a portion selectively receivable in one of the detent cuts on said rear cap, the breech end of the barrel being threadedly engageable with the receiver, a front bedding plate having an opening extending therethrough, said front bedding plate being receivable over the breech end of the barrel and held in abutting relation between the forward end of the receiver and the barrel, a stock attaching member for extending through the stock and threadedly engaging said front bedding plate for attaching the stock to the barrel and receiver, a slide block engageable with the breech bolt for actuating the breech bolt between forward-locking and rearward-unlocking movements relative to the receiver, a trigger pendulantly mounted relative to the receiver, a cammable spring-tensioned connector slidably mounted on said trigger for movement along its horizontal axis substantially in the axial direction of said slide block into and out of operating position and for movement upwardly and downwardly along its vertical axis, said connector having an inclining-declining cam on the upper surface thereof, a scar pivotally mounted on said slide block, a hammer pivotally mounted on said slide block and reciprocable therewith on the rearward stroke of said slide block, said hammer being contactable with said buffer plate for actuation into a full cock position, said hammer and sear having complemental portions for holding said hammer ina cocked position during the forward movement of said slide block to the forward closed firing position, said hammer acting on the cam of said connector and camrning said connector downwardly on the rearward and forward stroke of said hammer, said hammer having carnming portions for camming against said butter plate into a full cocked position with one of the camming portions effectuating a change to a more unfavorable cocking leverage prior to the final stoppage of the rearward travel of said hammer and with said hammer being held by said sear preparatory to the forward movement of said slide block to the forward closed firing position.

References Cited in the file of this patent UNITED STATES PATENTS 768,665 Johnson Aug. 30, 1904 1,090,351 Swebiluis et al. Mar. 17, 1914 1,149,795 Swebiluis et al. Aug. 10, 1915 1,672,534 Kramer June 5, 1928 1,827,037 Pedersen Oct. 13, 1931 1,907,164 White May 2, 1933 2,035,539 Dicke Mar. 31, 1936 2,049,776 Hyde Aug. 4, 1936 2,108,060 Green Feb. 15, 1938 2,321,592 Green et al. June 15, 1943 2,451,624 Loomis et a1 Oct. 19, 1948 2,615,370 Koucky Oct. 28, 1952 2,659,994 Yale Nov. 24, 1953 2,719,375 Crittendon et al Oct. 4, 1955 2,775,835 Gaidos Jan. 1, 1957 2,789,479 McColl Apr. 23, 1957 

